The Union Pacific Railroad bought 45 4-8-4s in three orders from the American
The first order of 20 locomotives (road numbers 800 through 819) was delivered
in 1937. These were designated Class FEF-1 and were designed by UP's Motive
Power Group to have 77" drivers, 24.5 x 32 cylinders, a boiler pressure of
300 psi, and a weight of 465,000 lbs resulting in a tractive effort of 63,611
pounds (63,800 nominal).
The second order of 15 locomotives (road numbers 820 through 834) was delivered
in 1939. These locomotives were designated as Class FEF-2. They were
designed to have 80" drivers, 25 x 32 cylinders, a boiler pressure of 300
psi, and a weight of 483,000 lbs giving each a tractive effort of 63,750
pounds (63,800 nominal).
The last group of 10, Class FEF-3 were delivered in 1944 and were
assigned road numbers 835 through 844. These FEFs (Four-Eight-Four) were
designated Class FEF-3 and were very similar to the Class FEF-2's.
Comparing operating costs per mile in 1946:
The UP 800 Four-Eight-Fours saved UP $300,000/year in costs. The purchase
price for these engines was $150,000 in 1944 dollars. The 800s ran about
14,000 miles per month. Today these engines would cost around $10-11 per
mile. The 800s cast-steel locomotive frame which replaced many separate
parts by one single casting helped maintenance. Information provided
by Dan McNaughton.
There are four surviving UP 4-8-4s: number 814 in Council Bluffs, IA;
number 833 which was recently moved from Pioneer Park in Salt Lake City,
UT to the Ogden Union Station
Museum in Ogden, UT; number 838 at UP engine house in Cheyenne, WY and
number 844, which is operational, also at UP engine house in Cheyenne, WY.
Class FEF-1 (Locobase 8339)
Data from UP 11 - 1946 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were 68808-68826 in August 1937, 68827 in September.
These engines were worked hard in service and responded exceptionally well. They were fitted with unusual tapered main and side rods, which reduced the mass of steel out at the end of the rotary motions. In addition, each wheel crank pin had its own sleeve bearing, which reduced the strain on the main crank pins on each side. These engines were reported as frequently running at above 100 mph.
They arrived in three batches, two (FEF-1 & FEF-3) which had Type A superheaters. These are shown in this entry (FEF-1) and Locobase 8340 (FEF-3). This first set had the smaller drivers 77") and a boiler pressed originally to 260 psi. Leading and trailing truck roller bearings were supplied by SKF while Timken produced those for the driving axles.
FEF-2s had the Type E superheater, which resulted in a very different boiler layout; see Locobase 284.
After diesels bumped the big oil-burners from passenger service, they turned their 80" drivers to freight work. The first was retired in 1954, the last in 1961.
Class FEF-2 (Locobase 284)
Data from UP 11 - 1946 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were 69161-69165 in August 1939, 69166-69172 in September, 69173-69175 in October.
Note that the diagram does not give a grate area, presumably because these were oil burners.
As outlined in Locobase 8339, these 4-8-4s were the premier passenger power on the Union Pacific. When the UP returned to the Alco for more of these enormous locomotives, the builder supplied these 15 with a Type E superheater installation with much more superheater area. The engines arrived with 80" drivers, 300-psi boilers, and roller bearings on all axles. (820-829 had Timken bearings, 830-834 were fitted with SKFs.)
The railroad bought ten more FEFs in 1944; see Locobase 8340. As the railroad dieselized in the 1950s, the FEF-2s gradually left service. The first was retired in 1956, the last in 1962.
Class FEF-3 (Locobase 8340)
Data from UP 11 - 1946 Locomotive Diagram book supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers were 72782-72791 in December 1944.
When World War II traffic levels over-stressed the existing UP passenger-locomotive stud, the railroad returned to Alco for ten more of the FEF design. They might have preferred to buy diesel sets, but those were not available. Instead, Alco produced engines with the power dimensions and driver diameters of the FEF-2 (Locobase 284) under a boiler virtually identical to that of the FEF-1 (Locobase 8339). And like the FEF-1, SKF supplied the leading and trailing truck roller bearings while Timken produced those for the driving axles.
Although delivered with 69.5 sq ft (6.45 sq m) of arch tubes, these were removed in 1945.
The last of the class - 844 - never actually left service. Its 1957-1959 stint of freight work was its last revenue work, but it was reserved for excursion work in 1960. Renumbered for a time as 8444, the locomotive regained its original number in 1969 after the diesel that bore 844 was retired. It was reassigned to excursion work and ran into the 21st Century.
The other 9 were all retired in 1957-1962.